396 METHODS OF ANALYSING GALL-STONES. [BOOK II. 



SECT. 3. THE METHODS OF ANALYSING GALL-STONES. 



The gall-stone is powdered and the powder is repeatedly treated 

 with boiling water, which extracts the bile with which most calculi 

 are imbibed. The residue is dried and then extracted repeatedly 

 with a mixture of equal parts of alcohol and ether, which removes 

 the cholesterin. The insoluble residue is then treated with dilute 

 hydrochloric acid, when, if calcium carbonate be present, effervescence 

 is observed. The insoluble matter, after treatment with hydrochloric 

 acid, is thoroughly washed with water. After drying, it is treated 

 with chloroform. The method of separation and purification of bili- 

 rubin is that described at page 316. The hydrochloric acid solution 

 in the above process will contain any copper which may be present 

 in the concretion and which will be readily discovered by the 

 ordinary tests. 



The methods of quantitative analysis to be employed depend 

 somewhat upon the constitution of the calculus. From the hints 

 given above and from the full information given previously as to the 

 determination of the various constituents of the bile which occur in 

 gall-stones, it will be easy to conduct the quantitative analysis of any 

 gall-stone. 



